Q: iPod to iPod music transfer

My apologies in advance for not taking the time to search these forums for the correct answer but my mind is elsewhere at the moment.

My father recently passed and left behind a 2nd gen iPod with 170 songs that my mother desperately wants to listen too. He bought her a 4th gen iPod a while ago, which she has never taken out of the box. It's special to her because my dad had it engraved with a nice message, which is why she wont simply listen to his iPod. Also, he had Parkinsons, so his is pretty beaten up and just barely working. 

I've committed to helping her get his music on her iPod, however I've having some difficulty. I have a MacBook Pro with the most current version of iTunes which all my music is backed up too. Honestly, sometimes I hate iTunes. Is there anyway for me to get his music to her iPod without loosing it, or adding all of my music? Is there a 3rd party software that will let me drag and drop 170 songs? Is there a way to do it from my Windows based PC at work?

Any help would be greatly appreciated.